Notched tooth and retainer



8, 1967 w. M.TROEPPL ET AL 3,305,954

NOTCHED TOOTH AND RETAINER Filed Oct. 22, 1965 73c INVENTORS 43c 74wllham M. Troeppl FE g 8 8 John G. Benetti Fig.1

United States Patent Ofiice 3,305,954 Patented Feb. 28, 1967 3,305,954NOTCHED TOOTH AND RETAINER William M. Troeppl, Santa Clara, and John G.Benetti,

Cupertino, Califl, assignors, by mesne assignments, of

one-half to Gerald A. Petersen, Sunnyvale, Calif., and

one-half to Anita E. Petersen, Saratoga, Calif.

Filed Oct. 22, 1965, Ser. No. 501,492 9 Claims. (Cl. 37-142) Thisinvention is a continuation-in-part of applicants co-pendingapplications, Serial No. 369,780 filed May 25, 1964, and Serial No.390,443 filed August 18, 1964, and is an improvement on Petersen PatentNo. 2,968,880. The invention relates to a new and improved earth-diggingtooth and holder having notches in the tooth and cooperating means onthe tooth and holder to resiliently fit into the notches to retain thetooth in the holder.

The tooth illustrated and described in Petersen Patent No. 2,968,880provides a hard, unitary tooth for an earthdigging machine having atapered distal portion which performs the digging function and abifurcated proximal portion composed of two prongs separated from eachother by a rectangular slot which extends forwardly from the proximalend of the tooth. In that patent there is further illustrated anddescribed a tooth-holder formed with a pair of recesses extendingrearwardly from the forward end so that the holder as viewed in frontelevation is substantially H-shaped with a web dimensioned substantiallyto fill the slot in the proximal end of the tooth. To hold the tooth inthe holder against unintentional dislodgement there is further provideda resilient insert which is compressed between surfaces of the toothprongs and walls of the recesses. The resilient insert, being locatedwithin the tooth-holder, is protected from wear and abrasion and furtherits resilient nature accommodates minor variations in the constructionof the tooth and holder, thereby making close tolerances unnecessary andfurther accommodating wear of the parts with the passage of time.Particular advantages of the tooth and holder are the facility withwhich the tooth may be installed and removed and the fact that nospecial tools are required for such purpose. The present inventionaffords many of these advantages.

. Although the teeth and holders in accordance with the above identifiedpatent have enjoyed widespread commercial success, certain opeartingconditions create an environment for' which the hereinafter describedtooth and holder are particularly suitable. A typical example occurswhen a lubricant is employed in the cutting operation or when the natureof the earth being cut is particularly slippery. Under such conditionsthe natural frictional engagement of the resilient insert with the sidewalls of the prong of the tooth and of the web of the holder isdiminished, sometimes permitting the sliding of the tooth relative tothe holder. Further, where severe operating conditions and intensevibration of the tooth are encountered there is also a tendency for thetooth to be dislodged from its holder. It is a principal purpose andobject of the present invention to provide means on the tooth and holderto enhance the retention of the tooth and to prevent unintentionaldislodgement of the tooth.

In one form of the invention hereinafter illustrated, the flanges of theH-shaped holder are partially closed off by transverse straps parallelto the web, the inward faces of the straps having protuberances. Thecontiguous outer surfaces of the prongs of the tooth are provided withnotches which mate with the protuberances in the assembled position ofthe parts. Hence the resilient insert is either replaced or augmented ineffect by the lodging of the protuberances in the notches on the sidesof the prongs.

In another form of the invention the notches on the prongs aretransversei.e., on the top and bottom surfaces similar to the notchesshown in Petersen Patent No. 2,877,574. Transverse flexible pins fitthrough one or more holes in the web of the holder and lodge in thenotches in the assembled position of the parts, thereby preventingunintentional withdrawal of the tooth from the holder. However, theholder is so constructed that the pin can flex under sufficient stressto intentionally drive the tooth from the holder, permitting extractionof the tooth without removal of the pins.

In one form of the invention of the type heretofore described, a singletransverse pin is used. Another form hereinafter described uses a stapleor hairpin-shaped pin passing through two holes in the web and engagingnotches in both the tops and bottoms of the prongs.

In still another form of the invention, notches similar to those lastdescribed are formed in the top or bottom surfaces of the prongs. Thecooperating wall of at least one of the flanges of the holder is formedwith a protuberance which lodges in the notch in the assembled positionof the tooth. Thus the tooth is restrained against unintentionaldislodgement. In order to hold the tooth and protuberance in engagement,a spring is installed between the opposite face of the prong and thewall of the recess which biases the tooth into engagement with theprotuberance. However, when it is desired to withdraw the tooth from itsholder suflicient force is exerted to overcome the resilient means andpermit the notch of the tooth to escape from the protuberance.

Still another feature of the invention is the provision of improvedmeans for dislodging the tooth from its holder when it is worn and mustbe reversed or replaced. For such purposes, holes are formed in the topand bottom flanges of the tooth-holder in registry with the forward endof the slot of the tooth. By driving a tapered instrument through thealigned holes, the tooth may be forced forwardly away from the holderdespite the retaining means, thus extracting the tooth. It will furtherbe understood that openings may be formed behind the prongs throughwhich an instrument may be inserted to drive the tooth forwardlyrelative to the holder.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawingsin which similar characters of reference represent corresponding partsin each of the several views.

In the drawings:

FIG. 1 is a top plan view, partly broken away in section, showing oneform of tooth, holder and retaining means.

FIG. 2 is a sectional view taken substantially along the line 2-2 ofFIG. 1.

FIG. 3 is a fragmentary side elevational view of a modifiedconstruction.

FIG. 4 is a transverse sectional view taken substantially along the line44 of FIG. 3.

FIG. 5 is a view similar to FIG. 3, of still another modification.

FIG. 6 is a sectional view taken substantially along the line 6-6 ofFIG. 5.

FIG. 7 is a fragmentary sectional view of another modification takensubstantially along the line 7-7 of FIG. 8.

FIG. 8 is a fragmentary sectional view taken substantially along theline 8-8 of FIG. 7.

Tooth 11 is subject to variation in shape and as illustrated hasforwardly convering top and bottom distal surfaces 12 extending acrossthe width of the tooth and terminating in a truncated front edge 14.Side edges 18 of the distal portion are substantially vertical andparallel, although they may converge slightly rearward- 1y. Asillustrated particularly in FIG. 1, tooth 11 may be reversed to reducethe requirement of sharpening of the tooth until the working portion ofthe tooth is exhausted. However, such reversability is not essential tothe present invention. Proximal prongs 19, or roots, are separatedfromeach other by slot 21 which extends forwardly from the proximal endof the tooth. In the form of the invention shown in FIG. 1, outer sidewalls 23 in prongs 19 converge rearwardly. Rearward ends 24 of prongs 19slant outwardly-forwardly, providing abutting ends 26 which bear therearward thrust against holder 31. The forward end 27 of slot 21 isrounded and is located forward of the front end 32 of holder 31. Asherein illustrated, edges 23, 24, 26, 27 are shown vertical, but it willbe understood that they may be formed beveled where convenience ofmanufacture so requires.

A feature of the form of the invention shown in FIG. 1 and 2, is theformation on the exterior or outward edges of each prong 19 of a notch33, which in normal position of the tooth is substantially verticallydisposed. The function of notch 33 is to cooperate in retaining tooth 11in holder 31, as hereinafter described. A further feature of the form ofthe invention, as shown in FIGS. 1 and 2, is the formation of serrations34 on the inward facing side edges of slot 21. Serrations 34 are inbuttress shape, having substantially transverse forward'walls 36 andrearwardly-outwardly slanted supporting walls 37.

The holder 31 herein illustrated may be fastened to an excavating toolor, as shown in FIG. 1, may be a connector connected to a primary holder41.

Holder 31 has a proximal end 32, which is essentially H-shaped in frontelevation in the sense that it has top and bottom flanges 42, 43extending outwardly in either direction from a vertical web 44. Thecrosssectional shape of web 44 is slightly less than slot 21, so thatthere is a slight clearance between the walls of web 44 and serrations34 of slot 21. The spacing between the opposed top and bottom walls ofthe flanges 42, 43 is slightly greater than the space between the topand bottom surfaces of prongs 19. The recesses in holder 31 terminate inend walls 46 against which points 26 abut. Openings 47 in holder 31behind prongs 19 provide a means for extracting tooth 11.

Extending transversely through Web 44 is a hole 51 which receives aresilient insert 52 formed of rubber, synthetic rubber such as neoprene,or the like, which is preferably circular in cross-section and of adiameter approximately equal to that of hole 51. The length of insert 52is substantially greater than the width of web 44 and preferably isabout equal to the width of holder 31. Web 44 is formed with grooves 53rearwardly of hole 51,.but the spacing is such that insert 52 issqueezed between serrations 34 and the bottom of grooves 53. Thebuttress serrations 34 dig into resilient insert 52 and augment thenormal resistance to the extraction of tooth which occurs by reason offriction.

Further, to secure tooth 11 in position in holder 31, straps 56 areformed extending between top and bottom flanges 42, 43cm either side ofholder 31 immediately outside of the side edges 23 of tooth prongs 19 inthe assembled position of the parts. Protuberances 57 are formed on theinner faces of straps 56, mating with notches 33 in side walls 23 oftooth prongs 19. It will be noted, as indicated by reference numeral 30,that forwardly of strap 56 the side of holder 31 is stepped inwardly.

When tooth 11 is to be installed, resilient insert 52 is placed in hole51 with the ends of the insert extending into the recesses on eitherside of web 44. Tooth 11 is forced rearwardly, the ends 26 of prongs 19bending the insert back into grooves 53 and deforming the insert toaccommodate the clearances between the parts. When the tooth isfull'y'installed, the'buttress teeth 34 grip into insert 52 and theinsert itself is squeezed in grooves 53 and elongated so that there isfrictional as well as mechanical resistance to withdrawal of tooth 11from holder 31. Additionally, the prongs 19 deflect inwardly untilprotuberances 57 slip into notches 33 thereby additionally locking tooth11 in place.

When it is necessary to extract the tooth from its holder when it mustbe reversed or replaced, the tooth is driven out by various means. Thusa tool may be inserted through openings 47 in the back of the recessesto engage the rearward ends 24 of prongs 19. Alternatively, semicircularcutouts 58 are formed in the front of the holder substantially inregistry with forward end 27 of slot 21. Hence a tapered tool (notshown) similar to a drift pin may be inserted in the aligned openings58, 27 to force the tooth to the left and as viewed in FIG. 1, and thusextract the tooth, despite the function of the retaining meansheretofore described.

By reason of the fact that tooth 11 is formed of a unitary piece ofhard, abrasive-resistant steel which, nevertheless, has a certain amountof malleability, materials which arequite abrasive may be dug andconsiderable shocks may be absorbed by the tooth during its diggingaction. Holder 31 is of a more resilient material which permits acertain amount of bending or flexure to absorb much of the stress of thedigging action. Essentially, therefore, holder 31 is of a less abrasiveresistant material than tooth 11.

Turning now to FIGS. 3 and 4, in this form of the invention resilientinsert 52 may be eliminated and web 44a substantially fills slot 21abetween prongs 19a. In this modification, transverse notches 61 may beformed in the top and bottom surfaces of prongs 19a, adjacent therearward ends of prongs 19a. Notches 61 are approximately semi-circular.It will be understood that although notches 61 are shown in both top andbottom, one set of notches may be eliminated. Web 44a is formed with atransverse hole 51a in registry with top notches 61- and the walls offlanges 42a are cut away in corresponding notches 62. The size ofnotches 62 is greater than notches 61 for a purpose which hereinafterappears.

The retainer for the form of the invention shown in FIGS. 3 and 4 is aflexible pin 63 which fits through hole 51a in web 44a projecting toeither side of the web and fitting into notches 61 to act as a key torestrain withdrawal of the tooth 11a from its holder 31a. Retainer 63 issufficiently flexible so that it can be deformed into the enlargednotches 62 in holder 31a to permit the tooth to be driven into place orto be extracted, but when tooth 11a is seated in assembled position pin63 is straight, fitting into notches 61 to hold the parts in place.

When it is necessary to extract tooth 11a, the tooth is driven forwardlyand pin 63 deflects into the enlarged notches 62 to permit withdrawal.It will be understood that instead of being located only on the top ofthe tooth, as shown in FIGS. 3 and 4, pin 63 may be located on thebottom or, alternatively, one pin may be used on the top and another pinon the bottom. In many other respects the elements of the inventionshown in FIGS. 3 and 4 resemble those in the modification of FIGS. 1 and2, and the same reference numerals followed by the subscript a areemployed.

FIGS. 5 and 6 show a modification of the form of the invention shown inFIGS. 3 and 4. In this form of the invention notches 61b are formed inboth the top and bottom surfaces of each prong 19b and correspondingnotches 62b are formed in the adjacent inward facing surfaces of the topand bottom flanges 42b, 4317. Also, a pair of holes 5111 is formed inweb 44]) in alignment with notches 6112. As a further feature, avertical groove 66 may be formed in side edge 23b of one prong 19binterconnecting notches 61b.

Retainer 67 is preferably a staple or U-shaped member. The parallel legs68 of the staple fit through holes 52b and in notches 61b. Theinterconnecting portion 69 of staple 67 fits in side groove 66. In otherrespects, staple 67 flexes to permit installation and extraction of thetooth in the same manner as pins 63 of the preceding modification andfurther functions to hold the tooth in position against unintentionaldislodgment.

In other respects the modification of FIGS. 5 and 6 resembles that ofthe preceding modifications and the same reference numerals are usedfollowed by the subscript 17.

The modification of FIGS. 7 and 8 employs a tooth similar to that shownin FIGS. 3 and 4. The same reference numerals followed by the subscriptc are used to designate corresponding parts. In this form of theinvention, however, a protuberance 71 is formed in the downward-facingwall of top flange 42c mating with notch 61c in prong 190. The clearancebetween the top and bottom of prong 19c and the facing walls of flanges42c, 43c is greater than in the preceding modifications. To hold tooth110 in place, a spring 72 is installed in the space below prong 19c,biasing the prong so that notch 61c fits protuberance 71 to restrainunintentional withdrawal of the tooth. The forward end of spring 72 maybe formed with a curl 73 which lodges in transverse groove '74 in bottomflange 43c to prevent displacement of spring 72. In this form of theinvention, when the tooth is installed spring 72 flexes to permit prong19c to move downwardly and allow protuberance '71 to slide on the top ofprong 19c until it nests in notch 610, as shown in FIG. 7. Thereafter,spring 72 holds the parts in assembled position. When it is necessary toextract the tooth, the tooth may be removed by means hereinbeforedescribed and during such removal the spring 72 again deflects to permitthe protuberance 71 to clear the notch. It will further be understoodthat whereas the protuberance 71 is shown 'on the top of the holder 31cand the spring 72 on the bottom, the arrangement may be reversed.

What is claimed is:

1. In earth digging equipment, a tooth formed of hard material having adistal portion formed with a cutting edge and a proximal portion havingtop and bottom faces formed with a longitudinal slot extending forwardlyfrom the proximal end of said tooth to divide said proximal portion intotwo prongs, said slot formed with substantially parallel, inward facingside Walls;

a tooth holder formed with a pair of recesses to receive said prongs,said holder having a web separating said recesses and dimensionedsubstantially to fill said slot;

and retaining means for retaining said tooth in said holder againstunintentional dislodgement, said tooth formed with at least one notch,said holder formed with at least one protuberance fitting in said notchin assembled position of said tooth and holder, said tooth andprotuberance being resiliently movable relative to each other to forcesaid protuberance and notch out of engagement to permit intentionalextraction of said tooth from said holder.

2. The combination of claim 1, in which said holder is generallyH-shaped in front elevation having a web and top and bottom projectingflanges and which further comprises a strap interconnecting the outeredges of flanges of said holder, said protuberance on said strap, saidnotch on the outer side edge of said tooth.

3. The combination of claim 2, which further com prises a resilientretainer compressed between said side walls and said web, said resilientretainer flexing to permit relative movement of said tooth and saidholder.

4. The combination of claim 3, in which said side walls are formed withtooth-like protuberances biting into said resilient retainer.

5. The combination of claim 2, in which the outer edges of said toothtaper inwardly-rearwardly, said notch formed in the inwardly-rearwardlytapering outer edges.

6. In earth digging equipment, a tooth formed of hard material having adistal portion formed with a cutting edge and a proximal portion havingtop and bottom faces formed with a longitudinal slot extending forwardlyfrom the proximal end of said tooth to divide said proximal portion intotwo prongs, said slot formed with substantially parallel, inward facingside walls;

a tooth holder formed with a pair of recesses to receive said prongs,said holder having a web separating said recesses and dimensionedsubstantially to fill said slot; said web formed with at least onetransverse hole, a notch formed in a surface of at least one said prongin alignment with said hole, and retaining means comprising a flexiblepin through said hole normally fitting in said notch, said holder formedrelieved to accommodate flexing of said pin away from said notch duringextraction of said tooth.

7. The combination of claim 6, in which said web is formed with a pairof transverse holes, at least one said prong formed with notches on topand bottom surfaces in alignment with said holes, said retaining meanshaving flexible legs fitting through said holes and normally fitting insaid notches, said holder formed relieved to accommodating flexing ofsaid legs away from said notches during extraction of said tooth.

8. The combination of claim 7, in which said retaining means has aconnecting portion interconnectnig said legs, said tooth formed toaccommodate said connecting portion.

9. The combination of claim ll, in which said notch is formed in aseries of a prong transverse to said web, said protuberance in a wall ofsaid recess facing said last mentioned surface, said retaining meansfurther comprising a resilient member interposed between said prong andsaid holder biasing said protuberance and said notch into engagement.

No references cited.

ABRAHAM G. STONE, Primary Examiner. A. E. KOPECKI, Assistant Examiner,

1. IN EARTH DIGGING EQUIPMENT, A TOOTH FORMED OF HARD MATERIAL HAVING ADISTAL PORTION FORMED WITH A CUTTING EDGE AND A PROXIMAL PORTION HAVINGTOP AND BOTTOM FACES FORMED WITH A LONGITUDINAL SLOT EXTENDING FORWARDLYFROM THE PROXIMAL END OF SAID TOOTH TO DIVIDE SAID PROXIMAL PORTION INTOTWO PRONGS, SAID SLOT FORMED WITH SUBSTANTIALLY PARALLEL, INWARD FACINGSIDE WALLS; A TOOTH HOLDER FORMED WITH A PAIR OF RECESSES TO RECEIVESAID PRONGS, SAID HOLDER HAVING A WEB SEPARATING SAID RECESSES ANDDIMENSIONED SUBSTANTIALLY TO FILL SAID SLOT; AND RETAINING MEANS FORRETAINING SAID TOOTH IN SAID HOLDER AGAINST UNINTENTIONAL DISLODGEMENT,SAID TOOTH FORMED WITH AT LEAST ONE NOTCH, SAID HOLDER FORMED WITH ATLEAST ONE PROTUBERANCE FITTING IN SAID NOTCH IN ASSEMBLED POSITION OFSAID TOOTH AND HOLDER, SAID TOOTH AND PROTUBERANCE BEING RESILIENTLYMOVABLE RELATIVE TO EACH OTHER TO FORCE SAID PROTUBERANCE AND NOTCH OUTOF ENGAGEMENT TO PERMIT INTENTIONAL EXTRACTION OF SAID TOOTH FROM SAIDHOLDER.